The present invention relates generally to electric field delivery to tissue regions. More specifically, the present invention relates to electric field delivery and ablation of target tissue regions, including cancerous cells and solid tumors, using improved ablation probes.
Several methods of tissue ablation are currently available. Existing techniques of tissue ablation typically rely on high-frequency heat inducing electric current to a tissue of a patient to create a lesion for cutting tissue, removing unwanted tissue (e.g., cancerous tissue), staunch bleeding, and the like. Common hyper-thermal tumor ablation techniques include use of high-frequency radio frequency (RF) or microwave sources to heat tissue in order to mediate heat-induced histological damage to the target tissue. RF thermal ablation techniques include, for example, application of high frequency current to cause ionic agitation and frictional heating to tissues surrounding one or more positioned electrodes. The thermally induced tissue destruction is non-specific to targeted tissue and destroys both healthy and non-healthy tissue. Treatment is typically “targeted” by attempting to limit or control application to a limited or desired region. Controlling treatment delivery in this manner, however, has been difficult and has shown limited success, and often unavoidably results in unwanted destruction of non-target or healthy tissue. More recent techniques, such as irreversible electroporation by application of high-voltage direct current, while more effective in reducing thermally mediated destruction, similarly cause damage and destruction indiscriminately to tissues subjected to treatment.
Thus, there is a need for minimally invasive ablation techniques that more selectively destroy targeted tissue while minimizing damage to non-target tissue.